From 72425b1218f1afc60b2e1449c09d94b9ecbd55ae Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Wed, 27 Mar 2024 12:23:35 +0000
Subject: [PATCH] serve webdav: fix webdav with --baseurl under Windows

Windows webdav does an OPTIONS request on the root even when given a
path and if we return 404 here then Windows refuses to use the path.

This patch allows OPTIONS requests only on the root to fix this.

This affects all the HTTP servers.
---
 lib/http/middleware.go      | 10 ++++++-
 lib/http/middleware_test.go | 54 ++++++++++++++++++++++++++++++++++---
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/lib/http/middleware.go b/lib/http/middleware.go
index 3ee5c0cdc..06b82278b 100644
--- a/lib/http/middleware.go
+++ b/lib/http/middleware.go
@@ -195,6 +195,14 @@ func MiddlewareCORS(allowOrigin string) Middleware {
 // MiddlewareStripPrefix instantiates middleware that removes the BaseURL from the path
 func MiddlewareStripPrefix(prefix string) Middleware {
 	return func(next http.Handler) http.Handler {
-		return http.StripPrefix(prefix, next)
+		stripPrefixHandler := http.StripPrefix(prefix, next)
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Allow OPTIONS on the root only
+			if r.URL.Path == "/" && r.Method == "OPTIONS" {
+				next.ServeHTTP(w, r)
+				return
+			}
+			stripPrefixHandler.ServeHTTP(w, r)
+		})
 	}
 }
diff --git a/lib/http/middleware_test.go b/lib/http/middleware_test.go
index 15d0b0525..845e28013 100644
--- a/lib/http/middleware_test.go
+++ b/lib/http/middleware_test.go
@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -329,8 +330,11 @@ var _testCORSHeaderKeys = []string{
 
 func TestMiddlewareCORS(t *testing.T) {
 	servers := []struct {
-		name string
-		http Config
+		name    string
+		http    Config
+		tryRoot bool
+		method  string
+		status  int
 	}{
 		{
 			name: "CustomOrigin",
@@ -338,6 +342,40 @@ func TestMiddlewareCORS(t *testing.T) {
 				ListenAddr:  []string{"127.0.0.1:0"},
 				AllowOrigin: "http://test.rclone.org",
 			},
+			method: "GET",
+			status: http.StatusOK,
+		},
+		{
+			name: "WithBaseURL",
+			http: Config{
+				ListenAddr:  []string{"127.0.0.1:0"},
+				AllowOrigin: "http://test.rclone.org",
+				BaseURL:     "/baseurl/",
+			},
+			method: "GET",
+			status: http.StatusOK,
+		},
+		{
+			name: "WithBaseURLTryRootGET",
+			http: Config{
+				ListenAddr:  []string{"127.0.0.1:0"},
+				AllowOrigin: "http://test.rclone.org",
+				BaseURL:     "/baseurl/",
+			},
+			method:  "GET",
+			status:  http.StatusNotFound,
+			tryRoot: true,
+		},
+		{
+			name: "WithBaseURLTryRootOPTIONS",
+			http: Config{
+				ListenAddr:  []string{"127.0.0.1:0"},
+				AllowOrigin: "http://test.rclone.org",
+				BaseURL:     "/baseurl/",
+			},
+			method:  "OPTIONS",
+			status:  http.StatusOK,
+			tryRoot: true,
 		},
 	}
 
@@ -354,9 +392,14 @@ func TestMiddlewareCORS(t *testing.T) {
 			s.Serve()
 
 			url := testGetServerURL(t, s)
+			// Try the query on the root, ignoring the baseURL
+			if ss.tryRoot {
+				slash := strings.LastIndex(url[:len(url)-1], "/")
+				url = url[:slash+1]
+			}
 
 			client := &http.Client{}
-			req, err := http.NewRequest("GET", url, nil)
+			req, err := http.NewRequest(ss.method, url, nil)
 			require.NoError(t, err)
 
 			resp, err := client.Do(req)
@@ -365,8 +408,11 @@ func TestMiddlewareCORS(t *testing.T) {
 				_ = resp.Body.Close()
 			}()
 
-			require.Equal(t, http.StatusOK, resp.StatusCode, "should return ok")
+			require.Equal(t, ss.status, resp.StatusCode, "should return expected error code")
 
+			if ss.status == http.StatusNotFound {
+				return
+			}
 			testExpectRespBody(t, resp, expected)
 
 			for _, key := range _testCORSHeaderKeys {